Release with Redirect (RwR) to Long Term Evolution (LTE) is a network-controlled inter-Radio Access Technology (IRAT) mobility feature for moving LTE/UMTS-capable User Equipments (UEs) from an access network utilizing Wideband Code Division Multiple Access (WCDMA) to an access network utilizing LTE when the UEs transition to lower activity states. RwR enables “chatty” UEs that have transitioned from LTE to Universal Mobile Telecommunications System (UMTS) due, for example, to a lack of LTE coverage or Circuit Switched FallBack (CSFB), to transition back to LTE more quickly.
RwR also allows active mode mobility for all UEs. It is mandatory for Release-8 (Rel-8) devices to support RwR functionality. It is optional for Rel-8 devices to support packet-switched (PS) Handover.
RwR improves LTE utilization by quickly moving UEs over to LTE after having been served, for different reasons, by UMTS.